Fluoride sensing with a PCT-based calix[4]arene

Coordination chemistry of calix[4]arene derivatives with lower rim functionalisation and their applications

“…Whilst a number of calix [4]arene-based chemosensors have been developed for the detection of anions, those mentioned already were also selective for cations. Kim and co-workers have developed a calix [4]arene chemosensor which has been attached via amido linkage to two coumarin moieites [289]. Most anionic receptors are based on ligating units in a macrocycle having Hbonding interactions with the anions, such as those reported for calix [4]pyrroles [290].…”

Calixarene-based anionic receptors

“…Calixarene derivatives 28 and 29 with two coumarin fragments as signal system and two amide binding sites behave as PCT sensors [47]. Compound 28 proved to be selective for F -but not for Cl -, Br -, I -, HSO 4 -, CH 3 COO -, and H 2 PO 4 -; the complexation is accompanied by reduction of the coumarin absorption band at λ 335 nm in the UV spectrum and its shift to longer wavelengths.…”

An imidazole based colorimetric sensor for fluoride anion

“…Molecules containing functional groups such as amides, ureas/thioureas, guanidinium and ammonium derivatives can effectively bind anions using directional hydrogen bonding interactions and these types of compounds have widely been used for the binding of anions [5][6][7][8][9][10][11][12][13]. In most of the synthetic chemosensors the optical signaling chromophore fragment is covalently linked to a neutral anion receptor containing urea, thiourea, amide, phenol or pyrrole subunits.…”